Automatic regulator for timepieces



April 23, 1957 Filed Aug. 28. 1947 G. S. ANDREWS AUTOMATIC REGULATOR FOR TIMEPIECES 3 Sheets-Sheet 1 J 52 0 /J E///. K /9 U 55 f1; /7'v 54 mw /5 x I i u u w I INVEN TOR. 620 745 A/Vfl/PE'W-S' Apnl 23, 1957 G. s. ANDREW$ 2,789,414-

AUTOMATIC REGULATOR FOR TIMEPIECES Filed Aug. 28, 1947 v s Sheets-Sheet 2 A ril 23, 1957 e. s. ANDREWS 2,789,414

AUTOMQTIC REGULATOR FOR TIMEPIECES Filed Aug. 28, 1947 3 Sheets-Sheet 3 HHHHHHHI will!!! uu INVENTOR.

United States Patent AUTOMATIC REGULATOR FOR TIMEPIECES George S. Andrews, Greenwich, Conn. Application August 28, 1947, Serial No. 770,971

3 Claims. (Cl. 58-109) This invention relates to timepieces and aims to provide an automatic regulator for timepieces.

The running rate of a timepiece such as a watch or clock is usually governed by the period of oscillation of a balance wheel controlled by a hairspring. This period of oscillation is a function of the moment of inertia of the balance wheel and of the stifiness of the hairspring. The design of most timepieces is such that the moment of inertia of the balance wheel can not be altered and the period of oscillation of the balance wheel can be regulated only by changing the stiffness of the hairspring. As the stiffness of the hairspring is increased, thespeed of oscillation of the balance wheel is increased. In the past, the stiflFness of the hairspring has been regulated by altering its effective length. As a rule, this has been accomplished through a lever mounted for pivotal movement about the axis of the hairspring and carrying a pair of curb pins which engage the hairspring. The curb pins immobilize the portion of the hairspring which is between them and the hairsprings outer end. As the distance between the outer end of the hairspring and the curb pins is increased, the hairspring is stiffened. After observing that a timepiece has lost or gained time over the course of a period such as a day, its running rate has been regulated by pushing the curb pins farther from, or nearer to, the end of the hairspring.

The regulation of timepieces in this manner results in a compromise at best. The torque exerted by the mainspring decreases as the mainspring runs down, with a corresponding decrease in the running rate of the timepiece. 7 In regulating the timepiece, the position chosen for the curb pins has been such that, during the period when the mainspring runs from fully wound to nearly rundown condition, the time gained is counter-balanced as nearly as possible by the time lost. This has proved to be a very serious limitation upon the length of the period during which a watch or clock may be satisfactorily run between windings.

It is not possible to remedy this defect by causing the curb pins to travel along a fixed are each time the mainspring runs from fully wound to rundown condition. Even in timepieces of identical design, there are very considerable difierences in the arcs which would have to be traveled by the curb pins to maintain a substantially constant running rate. Variations in the thickness and the composition of the mainsprings and hairsprings are among the principal causes of this.

I have discovered that it is possible, during the period from fully wound to nearly rundown condition of the mainspring, to cause the curb pins to travel back and forth along a regulable path. This path can be regulated in each individual timepiece in accordance with my invention both with respect to the length of the path and with respect to the position of the path. At one end of this path, the curb pins are in the position which causes the timepiece to keep accurate time when the mainspring is fully wound. At the other end, the curb pins are in the position which causes the timepiece to keep accurate time when the mainspring is nearly rundown. As a result, the diificulties referred to above are overcome and accuracy is increased to such an extent that a timepiece can be produced whose running time is greatly in excess of that of any previous timepiece with which I am familiar.

A timepiece is constructed in accordance with my invention by attaching the curb pins for the hairspring to a movable carrier. A movable lever is adapted to move the carrier with it. A driven member is connected with the lever and with the mainspring so that the lever and carrier are moved back and forth along a path whose length can be regulated, and which is preferably in the form of an are.

In order that my invention will be clearly understood by those skilled in the art, I will describe the specific embodiments of it which are illustrated diagrammatically in the accompanying drawings in which:

Fig. 1 is an elevation of a timepiece having a helical spring as the driven member of the automatic regulator;

Fig. 2 is a plan view of the timepiece illustrated in Fig. 1;

Fig. 3 is a reversed elevation of the timepiece illustrated in Fig. 1;

Fig. 4 is an elevation of a timepiece in which a spiral spring constitutes the driven member of the automatic regulator;

Fig. 5 is a plan view of the timepiece illustrated in Fig. 4;

Fig. 6 is a reversed elevation of the timepiece illustrated in Fig. 4; 1

Fig. 7 is a plan view of a timepiece in which the driven member constitutes a spiral cam;

Fig. 8 is an elevation of the timepiece illustrated in Fig. 7;

Fig. 9 is an elevation of an automatic regulator in which the driven member consists of an axially displaceable gear;

Fig. 10 is an elevation of an automatic regulator in which the driven member consists of an axially displaceable gear carrying a conical cam;

Fig. 11 is a plan view of an automatic regulator in which the driven member consists of a spiral cam with'a sloping face; and

Fig. 12 is an elevation of the regulator illustrated inv Fig. 11.

The timepiece illustrated in Figs. l-3, inclusive, is of the going arbor type. It includes a barrel 15 containing a mainspring (not shown) which is wound by means. of an arbor 16. The gear train, indicated generally at 17, is driven by the mainspring through the usual main gear 18, ratchet 19 and click 20. The escapement is of, the platform type. It includes a vertical balance staff 22 which supports the balance wheel 23 and the hairspring 24.

The effective length of hairspring 24 is governed by curb pins 26 which are carried by an arm 27, mounted for pivotal movement about the axis of the hairspring.

The arm 27 is in frictional engagement with a lever 28 also mounted for pivotal movement about the axis of the hairspring so that normally when the lever 28 is pivoted the arm is swung with it, but the position of the arm with respect to lever 28 can be adjusted as desired.

A shaft 30 is mounted between the plates 31, 32 and supports gear 33 and a cam 34. The cam 34 consists of a stiff helical spring whose bottom is held in fixed position by stop arm 35. The upper end of that spring pushes against washer 36 which is held -in position on' shaft 30 by a nut 37. The lever 28 is held against the upper face of the cam 34 by means of a spring 38. The

is connected wit-h the cam 34 through sleeve 41 so that the cam and gear are rotated together. The rotation of gear 33 is limited to about a single revolution in either direction by'means; of a pin 42 fixedto gear 33' and a stop 43- fixed to plate 32.

The operation of the mechanism which -I"- have describedis as follows: The position of lever 28 with respect to earn 34 which is illustrated in Fig. l is the position -which that lever assumes when the mainspring is fully wound. When the mainspring is in nearly rundown condition, the lever 23- is in the iero position, which isat about the bottom of cam 34. The lever is first maintained in itszero position and the arm 27 is turned vw'th respect; to it until the curb pins 2.51am in the position where the timepiece keeps accurate time when the mainspring is nearly rundown. Themainspring is next wound and the-nut36 is then screwed up or down until the upper portion of cam 34 against which the lever 28 is-enga-gedisat the pointwhere the position of curb pins 26 is; suchthat. the timepiece keeps accurate time when the mainspring is. thus wound. In this manner, both the magnitude of the arc traveled by the curb pins between fully wound" and nearly rundown conditions of the mainspring, and'the position of that arc, are accurate 1y fixed.

As the, wound mainspring unwinds and drives the clockwork mechanism, the cam 3'4is rotated by means of gears 33 and 40 and the lever 28 travels downwardly along the upper face of the helical spring constituting that cam until the cam has made one revolution, when rotation of the gear 33 and the cam 34 are stopped by means of the pin 42 and stop 43. As the lever 28 travels downward, the arm 27 is pivoted with and carries the curb pins away from the end of hair-spring 24, thus stiifening that spring. When the mainspring is wound, this operation is reversed.

In Figs. 4712 inclusive, as in Figs 14, the lever which swings the carrier for the curb pins is illustrated in the position which it occupies when the mainspring is fully wound; also, the arc traversed by the curb pins is regulated in a manner similar to that which has been described in connection with Figs. 1-3: When the lever is in the zero, or initial setting position, the curb pin carrier is moved" independently of its lever until the curb pins are l h pvs ion. which aus s he t mep to k p u a e ime when he leve is in its n tial s in p s o Then the mainspring is wound and theposition ofthe ve i adju ted. to bring he. curb p to the p i with a mainspring (not shown) which drives the train of ears, nd c te generally. at 8, throug main g ar 49- The escapenient includes a vertical staff 50, balance wheel 51 and hairspring 52. The curb pins 53 are carried by zn'rnj54 which is connected with lever 55 so that the arm is normally swung with the lever but their relative positions can be adjusted as desired. The cam 57 consists of a spiral, spring of stiff wire. The inner endof 57 is fixed to sleeve 58 which is attached to the arbor or main gear 49. The outer end of cam 57 is hooked, in, one of a series of slots in. a ring 61 which is att bed to main gear 49. The lever 55 has av cam follower 62 which is urged against the cam 57 by means of spring 63 m p n Theiero position of lever 55 is that which it assumes when follower 62 is at about the end of coil 57. ft the. init a e ting: o h urb p ns s made h he lever n th t p sit n. he mainspring is wound. preferably uutilg the lever occupies the position illustrated in Big. 5,. The outer end of'eam 57 is hooked in that slot of sleeve 58 which, through lever 55 and arm 54, places all) the curb pins 53 in the position where the timepiece will keep accurate time: when the mainspring isthus wound.

The cam 57 rotates with main gear 49 and contains at least as many turns as the number of revolutions made by that gear during the period when the mainspring un winds from fully wound to rundown condition. Consequently, las cam 57 rotates, the curb pins 53 are swung y arm 54 and lever 55. thr ugh the. arc requir to maintain accurate time. When the mainspring is wound, the direction of rotation not earn 57 is; reversed so that the lever 55 is returned to the position illustrated in Fig. 5.

Figs. 7 and 8 illustrate a, timepiece in which automatic regulation is accomplished through the use of a fixed cam and an adjustable lever. That timepiece is of the going arbor type and includes mainspring barrel 68, arbor 69, ratchet and click 71. The escapementineludes balance stall 7-3-, balance wheel 74 and hairspring 75. The curb pins 77' are carried by arm 78' which is adjustably connected with lever 79 so that the arm is normallyswung with that lever. Fixed to gear 80-to rotate therewith is-a spiral cam 31. A cam follower 82 on pivoted lever 83 is urged against cam 81 by spring 84. The levers 79, 83 are provided respectively with radial slots-86, 87 and are connectedto each other by means of pin 88-. Pin 88 is threaded so that it can: be held in chosen position along slot- 87 by means of nuts; 89, 90. When the mainspring is nearly rundown, the cam follower occupies'the'pocket 92 in cam 81. The lever formed by the two members-79, 83 is in the position for the initial setting of curb pins 77 when those members 79, 83 lie along a straight line. After the initial curb pin setting ismadewhile the lever is in that position, the mainspring is'wound; Nuts 89, are then loosened: and member 79*is rotated independently of member 83 until the curb pins 77-occupy theposition which insures accuracy when the mainspring: is thus wound. Nuts 89, 90 are thentightened and as the mainspring runs down, cam 81 is rotated by main gear-93 through gear-94 and gear 80. While lever 83' is pivoted by cam 81, the curb pins 77 are swung through the chosen are.

Fig.- 9 illustrates an automatic regulator incorporated in a timepiece of the going barrel type. Such a timepiece has a mainspring barrel 97, main gear 98, and winding gear 99. Theescapement includes a balance staff 101, hairspring 102, and balance wheel 105. Curb pins 103 are carried by'arm 104, adjust-ably-connected with a lever so that the arm is normally swung with that lever. The lever consists of a sleeve 105 and finger 107 frictionallymounted in the sleeve so that the extent to which it projects therefrom can be regulated. A gear 103 is fixed to a threaded shaft 109 and meshes with winding gear 99. A gear which meshes with the main gear 98 isfixed' to sleeve 111 mounted on shaft 112. The sleeve 111 is threaded internally to receive threaded shaft-109. The end of finger 107- is held against the inner face of gear 1-10 by spring- 114.

As the mainspring unwinds, main gear 98 rotates gear 110 and winding gear 99-holds gear 108 in stationary position. Through the action of the threaded shaft 109 and sleeve 111, the gear 110 is pulled upwardly when the mainspring unwinds, swinging the curb pins 103 through an arc. When themainspring is wound, winding gear 99 rotates gear 108 and main gear 98 prevents gear 110 from rotating, thus causing that gear to be returned downwardly to the position illustrated in Fig. 9.

Thezero-position of the lever formed by finger 107 and sleeve 106 is that which they occupy when gear 110 is raised to the point shown by dotted lines in Fig. 9.

The initial curb pin adjustment is made with the leverin that position. The-mainspringis then woundand the.

length of finger 107 is adjusted to bring the curb pins to the position which causes the timepiece to keep ac curate time when the mainspring isthus wound.

In Fig. 10, an ordinary horizontal type of escapement is shown. It includes a balance staff 120, balance wheel 121, and hairspring 122. A gear 124 fixed to threaded shaft 125 meshes with winding gear 126. Gear 127 is mounted on threaded shaft 125 and has fixed to it upper face a conical cam 129. The cam 129 is threaded internally to receive threaded shaft 125.

The curb pins 130 are carried by arm 131 which is adjustably connected with lever 132 so that the arm is normally swung with the lever. Screwed in pivot 134 is lever 135 whose end is adapted to bear against the plate 136 attached to lever 132. The plate 136 is urged against the end of lever 135 and that lever is held in contact with cam 129 through the action of a spring (not shown).

As the mainspring unwinds, gear 124 is held stationary by winding gear 126, and gear 127 is rotated by main gear 137 so that, through the action of threaded shaft 125 and earn 129, gear 127 is pulled upwards, thereby displacing lever 135 and swinging curb pins 130 through their chosen arc. Lever 132 is in the position for initial setting of the curb pins when lever 135 and plate 136 are parallel. When the mainspring is wound, the second curb pin setting is made by adjusting the length of lever 135.

The escapement illustrated in Figs. 11 and 12 is also of the horizontal type. It includes a balance staff 140, balance wheel 141 and hairspring 142. A gear 144 which is connected with the mainspring gearing (not shown) is fixed to shaft 145. A cam 146 is mounted on shaft 145 for sliding movement and is adjustably connected with gear 144 through set screw 147. The cam 146 is in the form of a spiral. The face of the cam is vertical at the inner end of that spiral, but slopes inwardly at a constant rate as it reaches the outer end of the spiral. The curb pins 148 are carried by an arm 149 which i adjustably connected with lever 150 so that the arm is normally swung with the lever. The end of lever 150 is urged against the face of cam 146 by spring 151.

As the mainspring unwinds, cam 146 is rotated in a clockwise direction until the end of lever 150 bears against the inner end of the spiral, at which time the lever is in zero position and the mainspring is in nearly rundown condition. After the initial curb pin setting is made in this zero position, the mainspring is wound and the height of cam 146 is adjusted by turning set screw 147 until the curb pins occupy the desired position for the thus wound condition of the mainspring.

The embodiments of my invention which I have described are illustrative and the terms which I have used are terms of description and not of limitation. It will be appreciated by those skilled in the art that various changes may be made in the embodiments of my invention which I have described and that my automatic regulator may be combined with various types of clockwork mechanisms Without departing from the spirit of my invention as it is defined in the appended claims.

What I claim is:

1. In a timepiece having a mainspring and a hairspring, an arm mounted for pivotal movement, curb pins carried by said arm and engaging the hairspring adjacent its end, a longitudinally adjustable lever mounted for pivotal movement and adapted to swing said arm therewith, and a movable member engaged by said lever and driven by a gear connected with the mainspring to swing the lever and said arm.

2. In a timepiece having a mainspring and a hairspring, an arm mounted for pivotal movement, curb pins carried by said arm and engaging the hairspring adjacent its end, a lever mounted for pivotal movement and adjustably connected with said arm so that the arm is normally pivoted with it, a second lever mounted for pivotal movement and having an adjustable sliding connection with said first named lever, a cam follower fixed to said second lever, and a spiral cam engaged by said cam follower and driven by a gear connected with the mainspring to swing said levers and said arm.

3. In a time piece having a mainspring, a hair-spring and curb pins engaging said hairspring, means for automatically regulating the running rate of said timepiece as the mainspring unwinds by causing the point at which the curb pins engage the hairspring to shift along the hairspring, comprising a curb pin carrier consisting of an arm mounted for pivotal movement to permit adjustment or" the point at which the curb pins engage the hairspring and effect an initial setting of said curb pins for a selected mainspring torque, and means actuated by the mainspring for reciprocating said carrier during the winding and unwinding of the mainspring, including an adjustable connection adapted to permit variations in the extent to which said carrier is reciprocated by the mainspring without disturbing said initial setting of the curb pins at the first named mainspring torque to eifect an independent setting of the curb pins for a second mainspring torque.

References Cited in the file of this patent UNITED STATES PATENTS 156,647 Muchin Nov. 10, 1874 474,008 Gibboney May 3, 1892 594,654 Schulte Nov. 30, 1897 

